its Japanese 俺の妹がこんなにかわいいわけがない means There is no reason my sister is so cute...
(there is no reason for my sister is so cute) is a Japanese light novel by Hushimi officials. The illustrations are in charge Zakihiroga speak. Dengeki Bunko (ASCII Media Works), the books already published since August 8, 2008 (as of May 2011) In addition to being published, this work with the original comic, drama CD, anime, games and other media Which is expanded.